Political sociology has been the subject of much theorising by those who wish to understand and explain the process of societal change and not a little action by those who have sought, and in some cases succeeded, in changing particular societies. Historically, there is ample evidence that patterns of societal change exist, especially as a consequence of technological innovation. Development and modernisation theory often suggests that a number of neo-Marxists argue that industrialisation has created a world capitalist order, rather than simply a number of capitalist societies. In this world capitalist order developing or Third World societies have become dependent hence the term dependency theory on advanced industrial societies. The Third World cannot develop or industrialise in the normal way, since their economies are an integral part of a world capitalist system. Dependency theory challenges both the traditional Marxist view of revolution, and development and modernisation theory.